/*
* Copyright 2009 Accenture. All rights reserved.
*
* Accenture licenses this file to you under the Apache License, 
* Version 2.0 (the "License"); you may not use this file except in 
* compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* @author Huan Liu (huanliu AT cs.stanford.edu)
*/ 
package com.acnlabs.CloudMapReduce.mapreduce;

/**
 * Collects the <code>&lt;key, value&gt;</code> pairs output by {@link Mapper}s
 * and {@link Reducer}s.
 *  
 * <p><code>OutputCollector</code> is the generalization of the facility 
 * provided by the Map-Reduce framework to collect data output by either the 
 * <code>Mapper</code> or the <code>Reducer</code> i.e. intermediate outputs 
 * or the output of the job.</p>  
 */
public interface OutputCollector {
  
  /** Adds a key/value pair to the output.
   *
   * @param key the key to collect.
   * @param value to value to collect.
   * @throws Exception
   */
  void collect(String key, String value) throws Exception;
}
